Advice on debugging possible exception or crash

[Cecil Ward]

My program is instrumented with a load of writeflns. At one point 
it looks as though it suddenly quits prematurely because the 
expected writeflns are not seen in the output. It could be that I 
am just reading the flow of control wrong as it goes ret, ret 
etc. I’m wondering if it is throwing an exception, or has a fault 
initiating a crash, perhaps even due to the fetching of arguments 
of one of the writeflns. In my limited experience, exceptions 
produce an error message though, and I’m not seeing anything. Any 
advice on how to debug this, silent termination ?

I don’t have a debugger on this machine, but on an x86-64 box I 
could use gdb if I first take the time to work out how.